cbe: port to new `std.io.BufferedWriter` API

when rebasing I gave up on the conflicts of src/link/C.zig and copied
the file from origin/master which was 710632b45cd7a7081af82af418eb3e405f7aa35e
fceec91f77Jacob Young committed on 7/1/2025, 11:35:28 PM· committed by Andrew Kelleyparent4dc3a94
15 files changedLine totals unavailable